1. Field of the Invention
The invention relates to a contact for an electrical connector, particularly to an improved contact which needs a lower insertion force to be inserted into a connector housing, and can have a better effectiveness of self-alignment so that it can be aligned with a corresponding contact passage when the contact is finally mounted in the connector housing.
2. The Prior Art
As shown in FIG. 1, a perspective view of a conventional contact 10 for an electrical connector (not shown) can be seen. The contact 10 is configured as an elongated post having a generally rectangular cross-section. The contact 10 consists of a body portion 11 which will have an interference fit with a dielectric housing (not shown) of the connector, and be mounted in the dielectric housing. A contact portion 13 is used to engage with a corresponding contact (not shown) in a mating connector (not shown) to achieve an electrical connection. And a terminal portion 12 is to be soldered to a substrate, such as a printed circuit board (PCB).
The prior art contact 10 as shown in FIG. 1 has four sides which are all smooth in nature. The contact 10 would be fixed to the dielectric housing depending on an interference fit of its four sides with the connector housing. Such a feature causes the contact 10 to need a very high insertion force to be inserted into a corresponding contact passage defined by the dielectric housing. A high insertion force easily causes a rupture of the electric housing defining the corresponding contact passage.
Furthermore, due to the high insertion force, the prior art contact 10 needs a large pressing device for inserting the contact 10. A device with a large size means that the device would occupy a large area and needs more material (therefore, higher cost) to construct it.
Finally, since all of the four sides of the contact 10 have an interference fit with the dielectric housing from the point that the contact 10 is inserted into the dielectric housing, if the contact 10 is not aligned properly when inserted into a corresponding contact passage defined by the housing, the misalignment cannot be corrected. In other words, if the contact 10 is initially not aligned properly when inserted into the corresponding contact passage, the contact 10 will also be misaligned when extended through the corresponding contact passage. Because of this, the contact cannot correctly reach its final mounting position and would affect the quality and reliability of the connector.
To overcome the disadvantages of the prior art contact 10, as shown in FIG. 2, another prior art contact 20 is proposed. Like the contact 10, the prior art connector 20 is also configured as an elongated post which consists of a body portion 21, a terminal portion 22 and a contact portion 23. However, in addition to these portions, the contact 20 further has a fitting portion 24 in the form of two projections 25 protruding from two lateral sides of the body portion 21, respectively. In the second prior art contact 20, only the projections 24 will have an interference fit with the connector housing defining the corresponding contact passage into which the contact 20 is going to be inserted. Thus, the insertion force needed for inserting the contact 20 into the housing can be reduced in comparison with the first contact 10. Furthermore, in the second prior art contact 20, the initial misalignment of the contact with the corresponding contact passage can be corrected by the fitting portion 24 when it is engaged with the dielectric housing.
Although, in comparison with the first prior art contact 10, the second prior art contact 20 needs a lower insertion force (therefore a smaller pressing device) to insert the contact 20, the insertion force needed therefor is still deemed quite high.
FIG. 3 is a diagram showing the relation between the insertion force (X-coordinate) and the distance (Y-coordinate) that the fitting portion 24 of the contact 20 is inserted into the corresponding contact passage. From FIG. 3, it can be seen that the maximum insertion force 4250 g (as indicated by arrow P) needed for inserting the contact 20 occurs when the fitting portion 24 is inserted into the corresponding contact passage about 0.1 millimeter. Thereafter, the force is lowered to 2750 g and kept thereon until the contact 20 reaches its final predetermined mounting position.
Furthermore, although the contact 20 can have a self-aligning ability, such an ability is not good enough since it can only be performed once (i.e., when the fitting portion 24 is engaged with the dielectric housing).
Accordingly, although the above mentioned contact 20 is proven to be better than the first mentioned contact 10, the insertion force needed is still deemed quite high and the self-aligning ability achievable thereby is not totally satisfactory. Thus, the contact 20 still needs to be further improved.
Therefore, an objective of the invention is to provide a conductive contact for an electric connector which needs a quite law insertion force to be inserted into a dielectric housing so as to substantially reduce the risk of rupturing the housing.
Another objective of the invention is to provide a conductive contact for a connector which needs a relatively low insertion force to be inserted into a dielectric housing so that the size of the pressing device for generating the insertion force can be quite small. This way, the area the pressing device would occupy and the cost for constructing the pressing device can be considerably reduced.
Still another objective of the invention is to provide a conductive contact for an electric connector, wherein the misalignment of the contact with a corresponding contact passage can be corrected twice by the connector itself when a first and second fitting portion of the contact are sequentially inserted into the dielectric housing.